Method for guiding accurate maintenance, operation and maintenance of urban pipe network by using SWMM model

Abstract

The invention discloses a method for guiding accurate maintenance, operation and maintenance of an urban pipe network by using an SWMM model. The method comprises the following steps: carding and generating a pipe network image map, confirming key nodes, confirming boundary adjustment, building a pipe network model, operating the SWMM model, checking sedimentation risk prediction and evaluation of a pipe section in a simulation area in an SWMM output report, and giving a sedimentation risk map. On the basis of the SWMM model, in combination with the pipe network topological relation, the actual sewage flow direction, the sewage discharge amount and the sewage discharge process, an intra-region drainage pipe network model is built, full-process and full-region simulation of a drainage system is achieved, the process of pipe networks of all key nodes and key regions can be quantified, the trend can be displayed, and the state can be evaluated; the defect that branch pipe sections and nodes in the middle cannot be detected in the traditional operation and maintenance process of a pipe network is overcome.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of sewer network operation and maintenance, and particularly relates to a method for guiding precise maintenance and operation of urban networks by using a SWMM model. BACKGROUND

[0002] Pipe clogging is a common phenomenon in sewer networks. Pipe clogging and deposition can affect the drainage capacity of the sewer network, causing the flow capacity of the drainage pipe to weaken, thereby causing poor drainage and triggering urban waterlogging and other problems. Water pollution leads to ecological problems. Long-term deposition in the pipe, organic matter in the sediment, under the action of microorganisms, produces toxic gases and acidic substances, causing pipe leakage and pollution of groundwater, so it is necessary to carry out dredging and dredging work on the sewer network. City pipe network dredging and dredging is a difficult task, the environment is bad, the efficiency of manual operation is low, and harmful gases such as methane in the pipe also have a great impact on the life and health of workers. Therefore, it is of great significance to study the deposition problem of drainage pipes for the stable operation of urban drainage systems.

[0003] In the prior art, in terms of pipe network deposition detection, the common method is to use CCTV detection and QV detection to conduct general survey of the pipe network, and some researchers also use models to evaluate pipe network deposition and its impact. Considering that most pipes often do not meet the design standard, and because of road conditions, housing construction and other problems, pipe dredging work is difficult and costly, and it is even more difficult to complete the dredging work of all pipes.

[0004] At present, the operation and maintenance management of the sewer network mainly relies on general detection, without pipe section deposition risk analysis. Whether a pipe section reaches the dredging standard is determined by the detection results and human experience. For key pipe sections, dredging is mainly concentrated on dredging of a certain type of pipe section or dredging of pipes at risk points where overflow occurs. There is a lack of research and analysis of easily deposited pipe sections. Therefore, it is urgent to establish a method for precise maintenance and operation of the pipe network. SUMMARY

[0005] In order to make up for the shortcomings of the prior art, the application provides a method for guiding precise maintenance and operation of urban networks by using a SWMM model, to solve the technical problem of large workload in the operation and maintenance management of the sewer network and the inability to accurately clean up.

[0006] To achieve the above purpose, the specific technical solutions of the application are as follows:

[0007] A method for guiding precise maintenance and operation of urban networks by using a SWMM model, comprising the following steps:

[0008] S1, combing the topological relationship of the pipe network.

[0009] S2, key node confirmation, combined with the image map, according to the actual situation of the park distribution, community distribution, shop distribution, and municipal road situation, important nodes are determined;

[0010] S3, determine the boundary condition, according to the sewage pipe network flow direction, branch pipe distribution, determine the sewage storage range of each node, according to the actual drainage process, calculate the sewage storage capacity of each node as the boundary condition of the model, at the same time, for the case of rainwater mixed into the sewage pipe network, according to the actual runoff setting, generate the pipe network system;

[0011] S4, pipe network model building, according to the pipe network information file and boundary condition in the pipe network system generated in steps S1-S3, build the SWMM model;

[0012] S5, model calibration and rating, combined with the measured flow, liquid level and water quality of the key nodes, the model parameters are calibrated and rated, and the pipe network model conforming to the present situation of the drainage of the research area is obtained;

[0013] S6, easy deposition pipe section prediction, using the pipe network model calibrated in step S5, comprehensively analyzing the drainage capacity in the region, viewing the pipe section flow velocity results in the simulation area in the SWMM output report, predicting and evaluating the pipe section deposition risk, and giving a deposition risk map to guide the accurate maintenance of the pipe network.

[0014] Further, the specific steps of building the SWMM model in step S4 are as follows:

[0015] The specific steps of building the SWMM model in step S4 are as follows:

[0016] S4.1, extract the pipe network system parameters in step S2, determine the characteristic parameters of inspection wells, pipes and pump stations; elevation, size, scale, slope, flow direction, shape data; set corresponding hydraulic model parameters;

[0017] S4.2, according to the actual flow direction, set the starting point and ending point of each pipe section, and input the parameters involved in the pipe network system into the SWMM model;

[0018] S4.3, make a boundary input file combined with the boundary condition of step S3, and input it into the SWMM model;

[0019] S4.4, build the pipe network model, calibrate the model combined with the hydrological and water quality monitoring data, and simulate and evaluate the transportation capacity of the drainage pipe network.

[0020] Further, the pipe flow calculation model in step S4.4 uses the Manning formula to represent the flow of all pipes and channels, and the calculation formula is as follows:

[0021]

[0022] where:

[0023] Q - flow

[0024] n - Manning roughness coefficient;

[0025] S - slope, either pipe slope or friction slope (i.e., head loss per unit length), depending on the flow calculation method used;

[0026] A - cross-sectional area;

[0027] R - hydraulic radius;

[0028] For pressurized pipes with a circular cross-section, the Hazen-Williams or Darcy-Weisbach formula is used instead of the Manning formula;

[0029] Hazen-Williams formula:

[0030] Q = 3.391 CAR 0.64 S 0.54 Equation 2

[0031] C - Hazen-Williams C factor, which varies as the inverse of the surface roughness coefficient; Darcy-Weisbach formula:

[0032]

[0033] g - acceleration due to gravity;

[0034] f - Darcy-Weisbach friction factor.

[0035] Further, the specific steps of the step S1 are as follows:

[0036] S1.1, selecting a simulation area, arranging the main drainage trunk and inspection well in the pipe network model according to the sewage pipe arrangement;

[0037] S1.2, importing the main trunk pipe (including pipe network nodes) by using ArcGIS software, checking the topological relationship of the pipe network in the model, and determining the simulation range, simulation pipe section and node according to the project requirements.

[0038] Further, the parameters input into the SWMM model in the step S4.2 include the inlet / outlet node, inlet / outlet offset, shape, length, roughness coefficient of the pipe, the well bottom elevation, well depth, initial water depth, and allowed superhigh of the inspection well, the sewage quantity into the system, and the position data of the outlet.

[0039] Further, the hydraulic model parameters set in the step S4.1 include the buried depth, slope and roughness coefficient of the pipe.

[0040] Compared with the prior art, the present application has the following advantages:

[0041] 1、 The present application is based on the SWMM model, combined with the topological relationship of the pipe network, the actual sewage flow direction, the sewage discharge amount, the sewage discharge process, and the drainage pipe network model in the region is built, the whole process and the whole region simulation of the drainage system is realized, the process of the pipe network of each key node and key area is quantifiable, the trend is displayable, and the state is assessable, which makes up for the deficiency that part of the pipe section and node cannot be detected in the traditional operation and maintenance process of the pipe network.

[0042] 2、 The present application is based on the SWMM model, fully considers the drainage process of the drainage system, can reasonably simulate the liquid level, flow, flow velocity and other states in each pipe section, combined with flow velocity analysis, can more accurately identify the deposition risk of each pipe section, judge the easy deposition area in the region, guide the pipe network dredging work, and can realize the accurate operation and maintenance of the pipe network. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 It is a flowchart of the present application;

[0044] Figure 2 It is a result graph of simulating the transport capacity of the drainage pipe network in the present application;

[0045] Figure 3 It is a schematic diagram of simulating the deposition position of pollutants in the present application. DETAILED DESCRIPTION

[0046] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings, it should be pointed out that the embodiments are only specific elaboration of the present application, should not be regarded as the limitation of the present application, the purpose of the embodiments is to enable those skilled in the art to better understand and reproduce the technical scheme of the present application, the protection scope of the present application should still be limited by the scope defined in the claims.

[0047] The geographic three-dimensional information in the present application can be obtained according to the three-dimensional map simulated according to the actual implementation of the ground, which can be obtained from the geographic information database in the prior art.

[0048] The present application will be further described below with reference to the accompanying drawings.

[0049] A method for guiding accurate maintenance and operation of urban pipe network by using SWMM model, comprising the following steps:

[0050] S1, combing the topological relationship of the pipe network

[0051] S1.1, selecting a simulation area, arranging main drainage trunk pipes and inspection wells in the pipe network model according to the sewage pipe arrangement.

[0052] S1.2, import the main pipe (including pipe network nodes) using ArcGIS software, check the topological relationship of the pipe network in the model, determine the simulation range, simulation pipe section and node according to the project requirements.

[0053] S2, key node confirmation

[0054] Determine important nodes in combination with image maps, according to the actual situation of park distribution, community distribution, shop distribution, and municipal road conditions.

[0055] S3, determine the boundary condition

[0056] According to the flow direction of the pipe network and the distribution of branch pipes, determine the sewage receiving range of each node, according to the population, land type, community type, engineering type, combined with the water use planning of the study area, refer to various urban drainage specifications, calculate the sewage receiving capacity of each node as the boundary condition of the model, and at the same time, according to the actual runoff setting, generate a pipe network system for the case of rainwater mixed into the sewage pipe network.

[0057] S4, build a pipe network model

[0058] S4.1, extract the pipe network system parameters in step S2, determine the characteristic parameters of inspection wells, pipes and pump stations; elevation, size, scale, slope, flow direction, shape and other data; set the corresponding hydraulic model parameters (including pipe burial depth, slope, roughness coefficient, etc.).

[0059] S4.2, according to the actual flow direction, set the starting point and ending point of each pipe section, and the parameters involved in the pipe network system, such as the inlet / outlet node of the pipe, the inlet / outlet offset, shape, length, roughness coefficient, etc.; the well bottom elevation, well depth, initial water depth, allowable superhigh of the inspection well; the amount of sewage entering the system; the position of the outlet and other data are input into the SWMM model.

[0060] S4.3, make a boundary input file combined with the boundary condition of step S3 and input it into the SWMM model.

[0061] S4.4, build the SWMM model, calibrate the model combined with liquid level, flow rate and water quality monitoring data; build a pipe flow calculation model, use the Manning formula to represent the flow of all pipes and channels, the calculation formula is:

[0062]

[0063] In the formula:

[0064] Q—flow rate

[0065] n—Manning roughness coefficient;

[0066] S—slope, pipe slope or friction slope (i.e. water head loss per unit length), which depends on the flow calculation method used;

[0067] A—cross-sectional area;

[0068] R—hydraulic radius;

[0069] For circular cross-section pressure pipe, Hazen-Williams or Darcy-Weisbach formula is used instead of Manning formula.

[0070] Hazen-Williams formula:

[0071] Q=3.391CAR 0.64 S 0.54 (2)

[0072] The meanings of the parameters are the same as above.

[0073] Darcy-Weisbach formula:

[0074]

[0075] g—acceleration of gravity;

[0076] f—friction factor;

[0077] The meanings of the remaining parameters are the same as above.

[0078] According to the analysis of the deposition position of the pipe network, the degree of pipe deposition is related to the flow velocity of the pipe, and the flow velocity is the main factor determining the degree of pipe deposition. The greater the flow velocity of the pipe, the less likely it is to deposit. Combined with the simulation results of the flow velocity of the pipe network, the flow velocity is classified, the position where the pollutants are easy to form is judged, and the pipe section prone to deposition is predicted.

[0079] S5, model calibration

[0080] The model parameters are calibrated and calibrated by combining the measured flow, liquid level and water quality of the key nodes, and the pipe network model conforming to the present situation of the drainage of the research area is obtained.

[0081] S6, prediction of pipe section prone to deposition

[0082] Using the SWMM model calibrated in step S5, hydraulic simulation is carried out, the drainage capacity in the region is comprehensively analyzed, the flow velocity results of the pipe section in the simulation region in the SWMM output report are viewed, the deposition risk of the pipe section is predicted and evaluated, and the deposition risk map is given to guide the accurate maintenance of the pipe network.

[0083] Taking a certain region as an example, the effectiveness and rationality of the method are illustrated.

[0084] Based on the present situation of the pipe network base data of the research region, the pipe network model is built by executing steps S1-S6, and the final image result is output.

[0085] Figure 2 To study the fullness simulation results of the pipe section of the regional drainage pipe network, the higher the fullness, the higher the risk of overflow and the greater the operating pressure of the pipe section. The risk area obtained by simulation is roughly similar to the area where overflow often occurs in the actual operation and maintenance process.

[0086] Figure 3 To study the regional sedimentation risk distribution map, the areas with high sedimentation risk, and the main high-risk pipe sections still mainly exist in the main trunk pipes at the end of the drainage system (the pipe sections outlined by the dashed line). In the operation and maintenance process, the main trunk pipes in this area will be focused on dredging work.

[0087] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for guiding the precise maintenance and operation of urban pipe networks using the SWMM model, characterized by: The following steps are involved: S1, sorting out the topological relationship of the pipe network; S2, key node confirmation: Combined with the image map, important nodes are determined based on the actual distribution of parks, communities, shops, and municipal roads; S3: Determine the boundary conditions. Based on the flow direction and branch distribution of the sewage pipe network, determine the sewage collection range of each node. Based on the actual drainage process, calculate the sewage collection capacity of each node and use it as the boundary condition of the model. At the same time, in the case of rainwater mixed into the sewage pipe network, set the actual runoff volume and generate the pipe network system. S4, building a pipe network model, building a SWMM model based on the pipe network information file and boundary conditions in the pipe network system generated in steps S1-S3; S5, model calibration, combining the measured flow, liquid level, and water quality of key nodes to calibrate the model parameters and obtain a pipe network model that conforms to the drainage status of the study area; S6, prediction of pipe sections prone to deposition, uses the pipe network model calibrated in step S5 to comprehensively analyze the drainage capacity in the area, view the flow velocity results of the pipe sections in the simulated area in the SWMM output report, predict and evaluate the deposition risk of the pipe sections, and provide a deposition risk map to guide the precise maintenance of the pipe network.

2. A method for guiding the precise maintenance and operation of urban pipe networks using the SWMM model according to claim 1, characterized in that: The specific steps of building the SWMM model in step S4 are as follows: S4.1, extract the pipe network system parameters from step S2, determine the characteristic parameters of the inspection well, pipeline, and pump station, including elevation, size, scale, slope, flow direction, and shape data; and set the corresponding hydraulic model parameters; S4.

2. Set the starting and ending points of each pipe segment according to the actual flow direction, and input the parameters involved in the pipe network system into the SWMM model; S4.3, create a boundary input file based on the boundary conditions in step S3 and input it into the SWMM model; S4.

4. Build a pipe network model, calibrate the model with hydrological and water quality monitoring data, and conduct a simulation assessment of the drainage pipe network's transfer capacity.

3. A method for guiding the precise maintenance and operation of urban pipe networks using the SWMM model according to claim 2, characterized in that: The pipe flow calculation model in step S4.4 uses the Manning formula to represent the flow of all pipes and channels, and the calculation is shown in Formula 1: Where: Q—Flow n—Manning roughness coefficient; S—slope, pipe slope or friction slope (i.e., head loss per unit length), depending on the flow calculation method used; A—cross-sectional area; R—hydraulic radius; For pressurized pipes with circular cross-sections, use the Hazen-Williams or Darcy-Weisbach formula instead of the Manning formula; The Hazen-Williams formula is shown in Formula 2: Q=3.391CAR 0.64 S 0.54 Formula 2 C is the Hazen-Williams C factor, which varies with the inverse of the surface roughness coefficient; the Darcy-Weisbach formula is shown in Formula 3: g——acceleration due to gravity; f——Darcy-Weisbach friction factor.

4. The method for guiding the precise maintenance and operation of urban pipe networks using the SWMM model according to claim 1 is characterized in that: The specific steps of step S1 are as follows: S1.

1. Select the simulation area and arrange the main drainage trunk pipes and inspection wells in the pipe network model according to the layout of the sewage pipes. S1.2, use ArcGIS software to import the main pipeline (including pipeline network nodes), check the topological relationship of the pipeline network in the model, and determine the simulation scope, simulation pipe sections and nodes according to project requirements.

5. The method for guiding the precise maintenance and operation of urban pipe networks using the SWMM model according to claim 2 is characterized in that: The parameters input into the SWMM model in step S4.2 include the pipeline's inlet node, outlet node, inlet offset, outlet offset, shape, length, roughness coefficient, inspection well bottom elevation, well depth, initial water depth, and allowable superelevation; the amount of sewage entering the system; and the outlet location data.

6. A method for guiding the precise maintenance and operation of urban pipe networks using the SWMM model according to claim 2, characterized in that: The hydraulic model parameters set in step S4.1 include the buried depth, slope, and roughness coefficient of the pipeline.

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